With the extensive application of electronic products such as mobile phones, laptop computers, and the products with capability of aiding hearing, etc., it has been found that the earphone of the above products has problems of winding, knotting, and inconvenience of taking and keeping in use, which has caused some troubles to users and even further made some users give up using earphone. In addition, when using the electronic products, the users cannot avoid electromagnetic radiation resulting from the electronic products, causing harm to the users' health. For example, when the user puts the mobile phone on his ear to communicate with other person, the electromagnetic radiation resulting from the mobile phone causes harm to the user's brain. It has been found from experiments and study that the harm resulting from electromagnetic radiation to the brain is reduced dramatically when the mobile phone keeps a distance away from the ear by, for example, replacing the speaker inside the mobile phone with a earphone. By this way, the harm resulting from electromagnetic radiation to the brain is reduced 99%.
Chinese patent No. 200510004919.9 discloses a mobile phone with a built-in non-radiation earphone and a built-in non-radiation earphone assembly in which a earphone line is wound by a winder built in the mobile phone, so that when the mobile phone is not used, the earphone line is wound into the mobile phone by the built-in winder, and thus avoid knotting, winding, and facilitate to take and use the earphone, as well as reduce dramatically the electromagnetic radiation. However, it is known from specification and the figures that drive means (a micromotor, or a spring, or a clockwork spring) in an earphone line retracting device directly drives the winder, and thus, when a micromotor is used as the drive means, because the micromotor rotates with high speed and low torque, it can not provide enough torque to make the winder rotate. If the torque of the micromotor is increased, the size of the micromotor is increased too, and as a result, the drive means can not be built in the small mobile phone. Even though the size of the mobile phone can be increased to accommodate a big motor, the members of the mobile phone can also be damaged or even the user can be harmed due to the high speed of the motor. In addition, when a spring or a clockwork spring is used as the drive means, the torque of the spring or of the clockwork spring is big or bigger enough, but winding distance is short, and thus, when the spring or the clockwork spring drives the winder, the retracting distance is short, and thus can not retract the line well.